A new study from the National Centers for Coastal Ocean Science (NCCOS) reports recent sediment samples from Guánica Bay, Puerto Rico contained some of the highest concentrations of PCBs, chlordane, chromium, and nickel ever measured in the history of the NCCOS National Status & Trends Program, a nationwide contaminant monitoring program that began in 1986. These concentrations represent toxic threats to corals, fish, and benthic infauna—organisms that burrow into and live in the seafloor.

The data collected serve as an ecological baseline against which coastal managers in Puerto Rico can measure future change and that can help assess the efficacy of pollution remediation and watershed management actions. The findings also illustrate the importance of geographically broad, long-term contaminant monitoring programs, which allow new data to be placed in national and historical perspective. The research was supported by NOAA’s Coral Reef Conservation Program as part of their work with the U.S. Coral Reef Task Force, which designated Guánica Bay as a priority watershed for coral conservation. Project partners included NOAA’s Restoration Center and the University of Puerto Rico, Mayagüez.